As fighting intensified, the Turkish military said it had killed another 33 militants of the Kurdistan Workers' Party (PKK), taking the rebel toll to 112 since the launch of its cross-border incursion Thursday evening.

PKK rebels "are trying to flee southwards in panic," a general staff statement said.

"Local Iraqi groups are expected to prevent members of the terrorist organisation -- the biggest enemy of regional peace and stability -- from entering their region and being given protection there," it said.

The warning raised the spectre of a potential confrontation with the autonomous region's Kurdish administration, and just hours later Baghdad called for a swift Turkish withdrawal.

A statement by Prime Minister Nuri al-Maliki's government urged Turkey "to withdraw its forces from Iraqi soil as soon possible" and specifically described the operation as "a threat to Iraqi sovereignty."

"The government of Iraq calls on Turkey to respect its sovereignty and unity and considers that the unilateral operation across the border is a threat to the region," the statement said.

Previously, Baghdad had appeared to accept Turkey's assertions that the offensive posed no threat to its territorial integrity.

Turkey and the Iraqi Kurds are both US allies, and the likelihood of armed confrontation between the two has been a major cause of concern for Washington as it seeks to avoid a relatively stable area of conflict-torn Iraq being thrown into chaos.

Ankara has long accused the Iraqi Kurds of tolerating and even aiding the PKK by providing them safe haven, weapons and ammunition.

The Turkish army confirmed one of its helicopters had been "destroyed," but gave no details of the incident. PKK rebels claimed to have shot down an attack helicopter Saturday in a border region near the town of Amadiyah.

The army said eight soldiers were killed Sunday, bringing their losses since Thursday to 15. The PKK claimed it had killed 47.

Earlier Sunday, the United States had also called on Ankara to wrap up its incursion as swiftly as possible.

"The shorter the better," US Defence Secretary Robert Gates said in Canberra.

Gates, who is expected in Ankara next week, suggested Ankara adopt economic and political measures to win over Turkey's sizeable Kurdish community and erode popular support for the PKK, listed as a terrorist group by Turkey and much of the international community.

"Just using the military techniques are not going to be sufficient to solve the problems," he said.

The United States is providing its NATO ally with real-time intelligence on PKK movements.

The Turkish army said its warplanes bombed dozens of rebel hideouts and ammunition depots Sunday, destroying facilities that form the PKK's "terrorist infrastructure."

It also reported close-contact fighting on the ground and claimed that rebel resistance "was broken to a large extent," with intelligence reports of internal PKK divisions over strategy.

The army did not disclose the locations of the raids, but Iraqi Kurdish sources reported intensive fighting in and around Hakurk, a PKK stronghold, some 20 kilometres (12 miles) from the Turkish border.

The Firat news agency, considered a PKK mouthpiece, reported air raids and clashes in the region of Zap, home to a major PKK base west of Hakurk and said about 5,000 Turkish soldiers and 60 tanks advanced towards nearby Haftanin.

The PKK and another militant Kurdish group called on Kurdish youths across Turkey and Europe to unleash urban violence in response to the offensive.

"If they want to wipe us out, our youths should make life in the cities unbearable," Firat quoted PKK leader Bahoz Erdal as saying. "Kurdish youths should unite... and burn hundreds of cars every night".

Erdal also slammed the United States and Iraqi Kurds for helping the Turkish operation.

Ankara says an estimated 4,000 PKK rebels are holed up in northern Iraq and use the region as a springboard for cross-border attacks as part of their campaign for self-rule in the Kurdish-majority region of southeast Turkey.

The conflict has claimed more than 37,000 lives since the PKK took up arms in 1984.

burs-su/ag